Breastfeeding: a key modulator of gut microbiota characteristics in late infancy.

The objective of this study was to investigate the impact of the most commonly cited factors that may have influenced infants' gut microbiota profiles at one year of age: mode of delivery, breastfeeding duration and antibiotic exposure. Barcoded V3/V4 amplicons of bacterial 16S-rRNA gene were prepared from the stool samples of 52 healthy 1-year-old Australian children and sequenced using the Illumina MiSeq platform. Following the quality checks, the data were processed using the Quantitative Insights Into Microbial Ecology pipeline and analysed using the Calypso package for microbiome data analysis. The stool microbiota profiles of children still breastfed were significantly different from that of children weaned earlier (P<0.05), independent of the age of solid food introduction. Among children still breastfed, Veillonella spp. abundance was higher. Children no longer breastfed possessed a more 'mature' microbiota, with notable increases of Firmicutes. The microbiota profiles of the children could not be differentiated by delivery mode or antibiotic exposure. Further analysis based on children's feeding patterns found children who were breastfed alongside solid food had significantly different microbiota profiles compared to that of children who were receiving both breastmilk and formula milk alongside solid food. This study provided evidence that breastfeeding continues to influence gut microbial community even at late infancy when these children are also consuming table foods. At this age, any impacts from mode of delivery or antibiotic exposure did not appear to be discernible imprints on the microbial community profiles of these healthy children.

Effects of difructose anhydride III on serum immunoglobulin G concentration and health status of newborn Holstein calves during the preweaning period.

This experiment was performed to investigate the effects of increases in passively acquired immunoglobulin G (IgG) by difructose anhydride (DFA) III supplementation on subsequent serum IgG concentration and health status in calves during the preweaning period. Thirty newborn female Holstein calves were paired by birth order, and 2 calves in each pair were fed 2 L of the same batch of colostrum within 2 h and at 10 h after birth, and followed by 2 L of the same batch of pooled colostrum at 20 h after birth. One calf from each pair was assigned to the control (n = 15) or treatment (n = 15) group. All calves in the treatment group received 18 g of DFA III at each feeding from birth to 7 d of age, whereas calves in the control group did not receive DFA III. Blood samples were collected before feeding at 0, 10, 20, and 36 h, and 4 and 7 d of age, and sampling was repeated at 7-d intervals thereafter until 49 d of age for serum IgG analysis. Calves were monitored daily for diarrhea and respiratory diseases. Serum IgG concentrations peaked at 36 h of age in both groups. Apparent efficiency of IgG absorption and peak serum IgG concentration were higher in the treatment group than in the control group. Using multiple regression analysis, we showed that peak serum IgG concentration in the newborn calves was positively correlated with colostral IgG concentration and DFA III supplementation. Moreover, peak serum IgG concentration (36 h of age) positively influenced subsequent serum IgG concentration until 35 d of age for all calves in both groups. The treatment group had higher serum IgG concentration from 20 h to 21 d of age than the control group. However, we detected no differences between the groups in number of calves with diarrhea or respiratory disease.

Plasma natriuretic peptide levels and daily physical activity in patients with pacemaker implantation.

To determine whether plasma ANP and/or BNP levels can be used to detect limitations in daily physical activity after pacemaker implantation, we measured plasma ANP and BNP levels at a pacemaker follow-up clinic in 56 patients (62+/-15 yrs, 2AAI, 9VVI, 34DDD, 7VDD and 4 rate-responsive modes), daily physical activity evaluated by a specific activity scale questionnaire (METs) and VO2 max obtained by expired gas analysis during ergometer exercise. A very close correlation (n=6, r=0.89, p<0.05) was obseved between. ANP in patients with daily physical activity class III (2-4 METs, n=21) was significantly higher than class II (5-6 METs, n=23, p<0.01) and class I (>7 METs, n=8, p<0.01), while BNP in class III patients was significantly higher than in class II (p<0.0001) and class I (p<0.0001) patients. Significant correlations between daily physical activity and BNP (r=-0.64, p<0.0001) and ANP (r=-0.43, p<0.001) were observed. Physiological pacing mode did not necessarily offer a better profile for BNP levels compared with non-physiological pacing modes. Patients with ventricular pacing (wide QRS: VDD, RR-VVI and VVI) showed significantly high ANP (p<0.01) and BNP (p<0.01) levels compared with those in patients with atrial pacing (narrow QRS: AAI and RR-AAI). During exercise, plasma catecholamines and ANP levels were significantly elevated, however, BNP levels, which were already elevated at rest, did not change significantly, and reflected a limitation of daily physical activity. The present study revealed that 37.5% of the patients displayed an elevation in BNP and this was judged to be a limitation of physical activity class III being equivalent to NYHA II or more. Elevated resting BNP levels reflected a limitation in daily physical activity in these patients. These findings suggested a third condition for physiological pacing--synchronization of ventricular contraction (narrow QRS pacing)--in addition to the two conventional conditions of atrioventricular synchrony and rate-responsiveness.

Suppression of temperature-sensitivity of a dnaA46 mutant by excessive DNA supercoiling.

We report here that the high-temperature sensitivity of a dnaA46 mutant was suppressed by addition of high concentrations of NaCl into the culture medium. This suppression was also observed with other high-temperature-sensitive dnaA mutants, except dnaA167 and dnaA508 mutants, which have mutations in the N-terminal region of DnaA protein. Since high concentrations of NaCl in the medium increased negative DNA supercoiling in a dnaA46 mutant, we hypothesized that the increase in DNA supercoiling is involved in the suppression of the temperature-sensitivity of the dnaA46 mutant by high concentrations of NaCl. This hypothesis was supported by in vitro and in vivo results as follows. A low DNA replication activity of purified DnaA46 protein at high temperatures was increased in line with an increase in DNA supercoiling of template DNA. The dnaA46 mutant showed higher sensitivity to nalidixic acid, a DNA-relaxing drug, than did the wild-type cells under the conditions of high temperatures and high concentrations of NaCl.

Clinical significance of increased plasma concentration of macrophage colony-stimulating factor in patients with angina pectoris.

OBJECTIVES: To determine the effect of macrophage colony-stimulating factor (MCSF) on atherogenesis in patients with coronary artery disease (CAD), we assessed the relation between the plasma concentration of MCSF and the incidence of acute coronary events in patients with CAD. BACKGROUND: Cytokines such as MCSF play a central role in inflammatory and proliferative responses in patients with acute coronary syndromes. However, the effect of MCSF on the clinical course in patients with CAD is still not known. METHODS: We measured the plasma MCSF concentration in 142 patients with documented CAD (62 +/- 9 years) and followed up for a mean period of 14 +/- 6 months. The study included 97 patients with stable angina (SA), 45 patients with unstable angina (UA) and 22 age-matched control subjects. The predictors of coronary events were analyzed by using a Cox proportional hazards model. RESULTS: The mean plasma MCSF concentration in patients with UA was significantly higher than that in patients with SA and in control subjects (981 +/- 277 vs. 693 +/- 223 vs. 680 +/- 158 pg/ml, p < 0.001). The mean plasma MCSF concentration in the 20 patients with coronary events was significantly higher than that in patients without coronary events (1,192 +/- 232 vs. 690 +/- 213 pg/ml, p < 0.001). The predictors of unfavorable outcome were an increased MCSF concentration, the presence of CAD and a low ejection fraction. CONCLUSIONS: These findings suggest that an increased circulating MCSF concentration reflects atherosclerotic progression in patients with CAD and predicts future cardiac events.

[Cytomegalovirus infection associated with immunosuppressive therapy in collagen vascular diseases].

OBJECTIVE: We investigated the frequency of cytomegalovirus (CMV) infection during immunosuppressive therapy in collagen vascular disease by using CMV antigenemia assay. METHODS: CMV antigenemia in fifteen patients with collagen vascular disease were analyzed before and one month after immunosuppressive therapy with more than 30 mg/day of prednisolone. RESULTS: CMV antigenemia were detected in 9 patients (60%), however no CMV antigenemia detected in all patients before treatment. In 7 of 9 patients CMV infection occurred such as fever, leucocytopenia, thrombocytopenia, liver injury, interstitial pneumonia. In 2 patients of polymyositis/dermatomyositis, creatine phosphokinase (CPK) levels which had decreased once just after treatment started, elevated again although initial dose of prednisolone continued. After ganciclovir administration because of the positive results of CMV antigenemia, elevated CPK levels were normalized immediately. CONCLUSION: Our results showed that CMV infection occurred with high frequency during immunosuppressive therapy, and might mimic the exacerbation of collagen vascular disease. It is important to differentiate CMV infection from increased activity of collagen vascular disease during the treatment.

Correlation between atrial natriuretic peptide and baroreflex sensitivity in patients with congestive heart failure.

The aim of this study was to investigate the relationship between baroreflex sensitivity (BRS) and humoral factors in patients with congestive heart failure (CHF). BRS was assessed by the phenylephrine method in 16 patients with CHF and in 13 healthy controls. The CHF group was subdivided into 2 groups according to BRS (group A: <6 ms/mmHg, n=9; group B: > or =6 ms/mmHg, n=7). BRS was markedly depressed in CHF than in the controls (4.8+/-2.0 vs 8.3+/-3.6 ms/mmHg, p<0.01), and lower in group A than group B (3.3+/-1.3 vs 6.7+/-0.6 ms/mmHg, p<0.01). The plasma human atrial natriuretic peptide (h-ANP) level in group A was significantly higher than in group B (54.6+/-27.6 vs 18.0+/-7.4 pg/ml, p<0.01), and a significant inverse correlation was observed between plasma h-ANP and BRS (r=-0.635, p<0.01). However, there were no significant differences between the 2 groups in plasma catecholamine concentration, plasma renin activity and cardiac function by echocardiogram. These findings suggest that the elevation of endogenous ANP may also serve to compensate for impaired BRS in patients with CHF, in addition to its principal actions, such as diuresis and vasodilation.

[Cold-induced reversible brain ischemia in mixed connective tissue disease, a case report].

A 19-year-old woman with long-standing mixed connective tissue disease was admitted for dizziness. We examined cerebral blood flow quantitation using 99mTc-hexamethylpropyleneamine oxime (HMPAO) and single photon emission computed tomography (SPECT) at rest and after cold pressor test. Mean cerebral blood flow reduced remarkably when she complained dizziness and showed peripheral Raynaud's phenomenon after cold exposure. We concluded cold-induced reversible brain ischemia was the reason of dizziness. Our finding suggests brain Raynaud's phenomenon. Further studies are necessary to clarify this phenomenon.

Coronary hyperreactivity to adrenergic stimulation and increased nocturnal vagal tone trigger coronary vasospasm.

The relationship between autonomic nervous system activity (ANA) and coronary vasoreactivity during transient myocardial ischemia was determined in patients with vasospastic angina (VA). ANA was measured by power spectral analysis of heart rate variability and humoral factors following intravenous infusion of insulin in 24 patients with VA and 6 control patients. Nine (38%) of the VA patients had significant ST segment depression (STD), and 4 of these patients had symptomatic STD. The frequency of anginal episodes in the 9 patients with VA and STD was significantly greater than that in the 15 VA patients without STD (3.4 +/- 3.1 vs 0.5 +/- 0.8 episodes/week, p < 0.05). The increase in the LF/HF ratio 30 min after insulin injection in patients with STD was significantly greater than that in patients without STD (34 +/- 31% vs 4 +/- 34%, p < 0.05). All of the patients with VA and STD had significant coronary vasospasm in response to the infusion of < or = 20 micrograms of acetylcholine, higher levels of nocturnal parasympathetic activity, and greater norepinephrine production in response to insulin stimulation than the VA patients without STD. These findings suggest that increased vagal tone and hyperreactivity to adrenergic stimulation may trigger vasospasm in patients with VA.

Significant characteristics of variant angina patients with associated syncope.

To determine whether syncope predisposes to sudden cardiac death, variant angina patients with syncope during cardiac attacks were compared with those without syncope. There were 240 consecutive patients (193 males and 47 females) diagnosed with variant angina pectoris. Thirty patients had a history of syncope during cardiac attacks while the remaining 210 had none. The incidence of cardiac events in the former group was 10.0% (3 of 30) and 10.5% in the latter. There were 3 cases of sudden cardiac death, all in the latter group. Significant clinical variables in the syncope patients included inferior ST-segment elevation and serious arrhythmias. We conclude that there is no relationship between syncope during variant angina and sudden cardiac death.

Prognostic indicators of major cardiac events in patients with asymptomatic coronary artery disease.

We investigated the role of myocardial ischemia in acute myocardial infarction and cardiac death in 253 patients with asymptomatic coronary disease (206 men, 47 women, mean age: 55 +/- 8 years). Patients were divided into two groups: those with angina pectoris with no history of myocardial infarction (AP group, 93 patients) and those with a history of myocardial infarction (MI group, 160 patients). We also examined the usefulness of exercise electrocardiographic and Holter electrocardiographic findings as prognostic indicators of cardiac events. After 24-hour Holter electrocardiograms were obtained in both groups, patients were assigned to subgroups with or without silent myocardial ischemia (SMI) based on the presence or absence of transient ST-segment depression. Prognostic indicators were evaluated by multiple regression analysis. Cardiac events occurred in 26 (10.3%) of 253 patients; in 6 patients these events were fatal. The incidence of cardiac events was significantly higher in the SMI group than in the non-SMI group (16.4% versus 5.6%, p < 0.05). SMI was identified as a significant prognostic indicator in the overall population (p = 0.0088), as were the number of diseased coronary arteries in the AP group (p = 0.0152), and SMI (p = 0.0022) in the MI group. There were 3 deaths related to cardiac events in each group. The mean time from onset of angina pectoris to death was 73 +/- 41 months compared with 33 +/- 43 months in the MI group. Our findings suggest that the severity of the coronary lesion and SMI were important predictors of major cardiac events, and that the mechanism of the onset of cardiac events was different in the AP and MI groups.

Monoclonal thyroglobulin autoantibodies: variable region analysis and epitope recognition.

A panel of human monoclonal thyroglobulin (Tg) autoantibodies (TgAAb) has been used to analyze autoantigenic determinants on human Tg and to investigate the relationship between variable (V) region gene sequences and epitope specificity. Two monoclonal TgAAb bound to the same (or closely related) epitope on Tg, and these were defined as type I TgAAb. Three other monoclonals bound to a different site and were defined as type II TgAAb. Inhibition studies with mixtures of type I and type II monoclonal TgAAb (Fab)2 preparations indicated that a mixture of the (Fab)2s almost completely inhibited (> 75%) labeled Tg binding to intact TgAAb in the sera of apparently healthy blood donors and patients with autoimmune thyroid disease (AITD). Type I TgAAb predominated in apparently healthy blood donors' sera, whereas type II TgAAb predominated in AITD sera. Analysis of V region gene sequences of the TgAAb indicated that a range of light chain and heavy chain genes from different gene families was used. Furthermore, the same germline genes that are used by TgAAb are also well represented in the genes coding for other self- and nonself-reactive antibodies. No homology in terms of light chain and heavy chain gene families, germline gene usage, or complementarity determining region sequences was observed in TgAAb directed to the same or closely related epitopes. Our studies show that TgAAb are directed to two major conformational epitopes on the Tg molecule and that the proportion of TgAAb directed to these epitopes in apparently healthy blood donors and that in patients with AITD appear to be different. TgAAb derived from different germline genes and with different complementarity determining region sequences can display similar epitope specificity, and this indicates that AAb directed to the same or a closely related epitope show considerable heterogeneity at the molecular level.

Cross-reactive idiotypes on high affinity IgG class human monoclonal thyroglobulin autoantibodies.

Anti-idiotypic antibodies have been developed in rabbits against three high affinity IgG class monoclonal human autoantibodies to thyroglobulin (Tg), which resemble polyclonal Tg antibodies in patients with autoimmune thyroid disease. Antibodies to 1E10 monoclonal anti-Tg (IgG2 kappa) recognised a cross-reactive idiotype (CRI) also present on 1D3 monoclonal anti-Tg (IG1 lambda) and on VB5 monoclonal anti-Tg (IgG2 lambda). The determinant to which anti-1E10 binds appears to involve, at least in part, the binding site for Tg. In contrast, anti-idiotypic antibodies raised against VB5 failed to bind to either 1E10 or 1D3, a finding consistent with previous studies on serum polyclonal Tg antibodies, which suggested that such antibodies exhibit a mixture of private and cross-reactive idiotypes. The observed sharing of idiotypic determinants was not related to subclass, light chain type or expression of a particular VH gene family in the heavy chain. Although binding of the anti-idiotypic antibodies to Tg antibodies in a panel of patients (including the donors of the lymphocytes used to produce the monoclonal antibodies) could not be detected, the monoclonal antibodies are representative of the donor patients' serum Tg antibodies, both in terms of IgG subclass and functional affinity. Thus these idiotypes may be present in patients' sera at levels below the detection limits of the assays employed. Cross-reactive regulatory idiotypes in mice often constitute a minor component of the anti-Tg repertoire. Consequently, it is possible that low levels of a CRI, such as the 1E10 CRI, may be involved in the regulation of the autoimmune response to Tg in man.

Circadian variation of ischemic threshold in patients with chronic stable angina.

Circadian variation of ischemic threshold in chronic stable exertional angina was determined in 51 patients with documented coronary artery disease from the Holter monitor results. The peak favored time zones of ischemic attacks were 8 a.m. and 9 a.m. There was no difference in frequency of ischemic attacks, magnitude of ST-segment depression, or duration of ST-segment depression between the two time zones for ischemic attacks, 6-9 a.m. and 0-3 p.m., but the ischemic threshold was lower in the morning than in the afternoon. These observations suggest that the pathogenesis of ischemic attacks differs from one time zone to the other and is considered helpful in planning therapeutic strategies for myocardial ischemia.

Surrogate thyroglobulin receptors and T cell proliferation in Hashimoto's thyroiditis.

Immunoglobulin molecules on the surface of a B lymphocyte are the endogenous "receptors" to which specific antigens bind. Studies in mice have shown that a monoclonal antibody, conjugated with palmitate to provide a lipid tail, can be inserted into the cell membrane to provide a "surrogate" antigen receptor. We have investigated whether a palmitate conjugate of a human monoclonal antibody specific for thyroglobulin (TG) could function as a surrogate TG receptor on blood mononuclear cells separated into fractions enriched for T cells or depleted of T cells (non-T cells). Using flow cytometry, we detected surrogate TG receptors on non-T (but not on T) cells from 11 of 11 individuals studied (5 Hashimoto patients and 6 control donors). In contrast, endogenous TG receptors could only be detected on non-T cells from 1 of 3 Hashimoto patients and from 0 of 4 control donors. Because of the efficient binding of TG by surrogate receptors on non-T cells, we assessed the ability of such cells to present TG to T cells. Proliferation in response to TG was observed in T cells from only 1 of 5 Hashimoto patients. This low frequency of response was no different from that previously detected using cultures of T cells and autologous dendritic cells. Therefore, the successful generation of surrogate receptors on non-T cells is not associated with more efficient TG presentation of T cells. Furthermore, the significance of the present study is that the T cells, not the antigen-presenting cells, are likely to be the limiting element in the T cell proliferative response to TG and other thyroid autoantigens.

Production and characterisation of a human monoclonal thyroid peroxidase autoantibody.

A human-mouse hybridoma has been produced by fusion of Hashimoto thyroid lymphocytes with the mouse myeloma line X63-Ag8.653. The cloned hybridoma secreted 2.5 micrograms per 10(6) cells per day of an IgG kappa thyroid peroxidase (TPO) autoantibody (2G4) with high affinity (2.5 x 10(9) molar-1) and specificity for human TPO. 2G4 did not react with lactoperoxidase, horseradish peroxidase or human myeloperoxidase or with porcine TPO or with human thyroglobulin. Plastic tubes coated with 2G4 bound about 50% of 125I-labelled human TPO added and the binding was inhibited by IgGs prepared from 18/18 TPO autoantibody-positive sera. This indicated that all 18 sera contained autoantibodies which recognised the same (or closely related) epitope as 2G4. Plastic tubes coated with IgGs from different TPO autoantibody-positive patient sera also bound 125I-labelled TPO but inhibition by 2G4 in this system was not complete. This suggested that the sera contained at least 2 types of TPO autoantibodies, with only one type of autoantibody reactive with the same epitope as 2G4.

[Silent myocardial ischemia in myocardial infarction patients: its prognostic significance].

To evaluate the prognostic and clinical significance of silent myocardial ischemia (SMI), we examined cardiac events in 160 patients with old myocardial infarction who underwent ambulatory Holter monitoring, treadmill exercise testing and coronary angiography. Using the Cox's proportional hazard regression model and the survival curves with the Kaplan-Meier method, we identified the predictors of cardiac events. The incidence of cardiac events for all the patients during the 44-month follow-up period was 18%. The significant predictors of unfavorable outcomes were severe coronary lesions and SMI. The incidence of SMI was 38%. The cardiac event rate in patients with SMI was higher than in those without SMI (32 vs 9%, p < 0.05). The most frequent cardiac event in patients with SMI was reinfarction, and the significant predictors of cardiac events for these SMI patients were lower ejection fraction and maximum ST depression on Holter monitoring. In conclusion, SMI proved to be a significant predictor of unfavorable outcome in patients with old myocardial infarction. It was, therefore, suggested that revascularization (PTCA/CABG) should be used as early as possible in patients with SMI whether anginal symptoms are present or not.

A new strategy for the reduction of acute myocardial infarction in variant angina.

To study the effects of stepwise early treatment in variant angina pectoris, frequencies of cardiac events and complications were examined after three different types of treatment. The subjects of the study consisted of 159 consecutive patients with variant angina pectoris, who were in need of hospitalization. The three treatment modalities were the introduction of calcium antagonists, nicorandil and nitroglycerin infusion, and percutaneous transluminal coronary angioplasty (PTCA), respectively. The cardiac event rate for this series of patients was 16% (25 of 159). The cumulative cardiac event rate was 22% at 1 year and 23% at 3 years in the first treatment period; 11% at the same intervals in the second treatment period; and 6% at the same intervals in the third treatment period. Our results suggest that it is important in the treatment of variant angina pectoris not only to prevent anginal attacks by the use of fast-acting coronary vasodilators, but also to initiate early revascularization.